Weist, who was 17 when the incident occurred, will be housed in the Idaho Department of Juvenile Corrections until his 21st birthday or the court terminates his IDJC custody, Decker said. There is also a chance Weist could be released on probation when he turns 21 if a judge approves, according to Decker.

Weist was also ordered to pay court costs and a $5,000 fine. He was also ordered not to contact the victim for the duration of his sentence.

Weist, of Nampa, stabbed his ex-girlfriend in the parking lot of Columbia High School last December. She was taken to a hospital and treated for injuries to her chest, arms and abdomen.

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“I attempted to kill the victim by stabbing her,” Weist said when asked about his actions at a previous court hearing. He told the judge he remembered stabbing the victim seven times.

The girl broke up with Weist a couple of months before the attack.

“All my frustration is directly related to (her),” Weist told a police detective, according to court documents. “When I was in a relationship with her … I felt very strong feelings for her and all I wanted was to give her love and support … and she just left me … saying she wasn’t interested in me. I blame her for my mental state today.”

Weist told police his father gave him the knife. The teen noted that he doesn't always carry it — only “if I feel the need to.”